REPRODUCTION AND DIVISION-OF-LABOR IN LEPTOGENYS SCHWABI FOREL (HYMENOPTERA-FORMICIDAE), A POLYGYNOUS, QUEENLESS PONERINE ANT

The combination of polygyny and natural queenlessness is uncommon in a nts. The ponerine ant Leptogenys schwabi Forel 1913 has no morphologic ally or anatomically distinct reproductive castes and several mated wo rkers in each colony, providing a model for the study of the effect(s) of polygyny on the social organization of a naturally queenless speci es of ponerine ant. L. schwabi also presents a case of queenlessness t hat is useful in comparative evolutionary studies of natural queenless ness because it is phylogenetically independent of previously-studied examples. Virgin laying workers were few unless mated workers were exp erimentally removed from the colony, indicating that their reproductiv e physiology is regulated by the mated workers. No physical interactio ns or oophagy were seen, implicating a pheromonal mechanism of regulat ion. The combination of queenlessness and polygyny did not affect the general pattern of division of labour. This may be attributed to the i nhibitory influence exerted by mated workers over virgin workers that forestalls the disruptive effects of reproductive competition among Vi rgin workers.